Here is the full list of all 29 The Assembly achievements.
Complete The Assembly
Madeleine is offered a job at the Assembly
Meet the Director
Read all the magazines in the waiting rooms
Escape The Assembly
Save the dog from Dr Chevez's experiment
Open the briefcase
Disable Silver Matter
Expel Gerard from his room
Listen to Benson's voice message to Larson
Hear Cal's Confession
Reach the 4th year in any round of the Outbreak trial
Retrieve your Portable Hard Drive
Discover the preperation for Madeleine's trials
Spot Dr Chevez
Complete your second trial
Gather all evidence
Give Larson's love note to Benson
Feed the dog
Complete your first trial
Find the Casius-D dossier
Find the sandwich in samples fridge
Meet Dr Chevez
Discover Anton's investigation into the Director's illness
Continually stare at Dr Chevez
Attempt to leave the second trial with a dagger
Complete the obsolete Pillar Trial
Discovered the Cryo experiment
Collect all Project Dossiers